BioMarin Reports Encouraging Preliminary Data on BMN 110 for MPS IVA

Phase III Trial Expected to Start by Q4 2010 or Q1 2011
Conference Call and Webcast to Be Held Today at 5:00 p.m.
ET

NOVATO, Calif., Feb. 4 /PRNewswire-FirstCall/ -- BioMarin
Pharmaceutical Inc. (NASDAQ:BMRN) today
announced an update on the Phase I/II trial for BMN 110 or
N-acetylgalactosamine 6-sulfatase (GALNS), intended for the
treatment of the lysosomal storage disorder Mucopolysaccharidosis
Type IVA (MPS IVA), or Morquio A Syndrome. Preliminary clinical
data from the first 24 weeks of the study (12 weeks at 0.1mg/kg and
12 weeks at 1.0 mg/kg) have been evaluated, and BioMarin plans to
announce top-line results for the full 36-week study after
completion of dosing at 2.0 mg/kg in the second quarter of
2010.

Key Observations:
-- Keratan sulfate (KS) levels fall within a few weeks after the start of
therapy.
-- Improvements in 6-minute walk distance and 3-minute stair climb at 24
weeks are consistent with those observed with clinical studies for MPS
I, MPS II, and MPS VI.
-- The frequency and severity of infusion reactions appear comparable to
those observed with Naglazyme and Aldurazyme.

"Although still early, we are encouraged by these initial
signals of efficacy of GALNS enzyme replacement therapy for Morquio
disease. Additional results will become available following the 2.0
mg/kg dose phase, but compared to other studies we have conducted
in MPS diseases, we feel encouraged by the reduction in KS and
improvements in walk distance and stair climb. Based on these
results, we feel more confident about endurance as a primary
endpoint for a Phase III trial and that a Phase III trial can be
conducted as expeditiously as previous trials of enzyme replacement
therapy," said Hank Fuchs, M.D., Chief Medical Officer of BioMarin.
"We plan to work closely with the FDA and other health authorities
to finalize a Phase III protocol after the completion of the
current study and have increased confidence that we will initiate a
Phase III registration-enabling program by the fourth quarter of
2010 or the first quarter of 2011."

Jean-Jacques Bienaime, Chief Executive Officer of BioMarin
added, "Based on these data, we are more optimistic about the GALNS
program as we continue to move closer to providing a treatment
option for Morquio patients. The number of Morquio patients
identified already exceeds the number of MPS VI patients on
Naglazyme, and an ERT for Morquio will fit perfectly into our
global commercial infrastructure without the need for significant
additional commercialization costs."

Mr. Bienaime continued, "2010 is shaping up to be an eventful
year for BioMarin. In addition to results from the Morquio Phase
I/II trial expected in the second quarter, we expect to report
Phase II PEG-PAL results in mid-2010 and Phase I BMN 195 results in
the third quarter of 2010. We look forward to keeping you updated
on the progress of our clinical programs."

GALNS Phase I/II Clinical Trial Design

The Phase I/II study is designed as an open-label,
within-patient dose escalation trial in approximately 20 patients
followed by a treatment continuation phase. During the dose
escalation phase of the study, subjects receive weekly intravenous
infusions of GALNS in three consecutive 12-week dosing intervals:
0.1 mg/kg for twelve weeks, 1.0 mg/kg for twelve weeks and 2.0
mg/kg for twelve weeks. The objectives of the Phase I/II study are
to evaluate safety, pharmacokinetics, pharmacodynamics, clinical
response to therapy and to identify the optimal dose of GALNS for
future studies.

The company has successfully developed and manufactures two
FDA-approved enzyme replacement therapies for the treatment of MPS
I and MPS VI. Naglazyme® (galsulfase) for MPS VI is wholly
developed and commercialized by BioMarin. Aldurazyme®
(laronidase) for MPS I is manufactured by BioMarin and marketed by
Genzyme Corporation.

Conference Call Details

BioMarin will host a conference call and webcast to discuss the
preliminary results of the Phase I/II trial of GALNS for MPS IVA
today, Thursday, February 4, at 5:00 p.m. ET. This event can be
accessed on the investor section of the BioMarin website at
www.BMRN.com.

Mucopolysaccharidosis IVA (MPS IVA, also known as Morquio A
Syndrome) is a disease characterized by deficient activity of
N-acetylgalactosamine-6-sulfatase (GALNS) causing excessive
lysosomal storage of keratan sulfate (KS). This excessive storage
causes a systemic skeletal dysplasia, short stature, and joint
abnormalities, which limit mobility and endurance. Malformation of
the thorax impairs respiratory function, and odontoid hypoplasia
and ligamentous laxity cause cervical spinal instability and
potentially cord compression. Other symptoms may include hearing
loss, corneal clouding, and heart valvular disease. Initial
symptoms often become evident in the first five years of life.
Depending on severity of the disease, age of diagnosis will
vary.

The rate of incidence of MPS IVA is as yet unconfirmed and
varies among different populations but estimates vary between 1 in
200,000 live births and 1 in 250,000 live births. There are several
studies that have documented the incidence as high as 1 in 76,000
live births in Northern Ireland. The estimated prevalence is
between 1,000 and 1,500 patients in the U.S., EU and Japan and
between 1,500 to 2,000 patients in the rest of the world for a
total of 2,500 to 3,000 patients. Approximately 400 patients
worldwide are currently registered in The International Morquio
Organization (IMO) survey and over 100 patients are already
registered in the BioMarin MorCAP registry program.

About BioMarin

BioMarin develops and commercializes innovative
biopharmaceuticals for serious diseases and medical conditions. The
company's product portfolio comprises four approved products and
multiple clinical and pre-clinical product candidates. Approved
products include Naglazyme® (galsulfase) for
mucopolysaccharidosis VI (MPS VI), a product wholly developed and
commercialized by BioMarin; Aldurazyme® (laronidase) for
mucopolysaccharidosis I (MPS I), a product which BioMarin developed
through a 50/50 joint venture with Genzyme Corporation; Kuvan®
(sapropterin dihydrochloride) Tablets, for phenylketonuria (PKU),
developed in partnership with Merck Serono, a division of Merck
KGaA of Darmstadt, Germany; and Firdapse(TM) (amifampridine
phosphate), which has been approved by the European Commission for
the treatment of Lambert Eaton Myasthenic Syndrome (LEMS). Other
product candidates include PEG-PAL (PEGylated recombinant
phenylalanine ammonia lyase), which is currently in Phase II
clinical development for the treatment of PKU; GALNS
(N-acetylgalactosamine 6-sulfatase), which is currently in Phase
I/II clinical development for the treatment of MPS IVA and BMN 195,
which is currently in Phase I clinical development for the
treatment of Duchenne Muscular Dystrophy. For additional
information, please visit www.BMRN.com. Information on BioMarin's
website is not incorporated by reference into this press
release.

Forward-Looking Statement

This press release contains forward-looking statements about the
business prospects of BioMarin Pharmaceutical Inc., including,
without limitation, statements about: the development of its
program for MPS IVA, and particularly the timing and conduct of
clinical trials related thereto, expectations regarding other
clinical and preclinical programs, and the potential market for
GALNS, if approved. These forward-looking statements are
predictions and involve risks and uncertainties such that actual
results may differ materially from these statements. These risks
and uncertainties include, among others: the results of current and
planned pre-clinical trials related to BioMarin's development
programs and particularly the enzyme replacement therapy for MPS
IVA; the content and timing of decisions by the U.S. Food and Drug
Administration, EMEA and other regulatory agencies, particularly
with respect to the enzyme replacement therapy for MPS IVA, the
actual number of MPS IVA patients in the developed world; and those
factors detailed in BioMarin's filings with the Securities and
Exchange Commission, including, without limitation, the factors
contained under the caption "Risk Factors" in BioMarin's 2008
Annual Report on Form 10-K. Stockholders are urged not to place
undue reliance on forward-looking statements, which speak only as
of the date hereof. BioMarin is under no obligation, and expressly
disclaims any obligation to update or alter any forward-looking
statement, whether as a result of new information, future events or
otherwise.